This goal of this study is to increase knowledge of the sources, environmental fate and health risks of chemical contaminants and their transformation products that have the potential to disrupt endocrine function in wildlife or humans - alkylphenol ethoxylate metabolites (APEMs), polybrominated diphenyl ethers (PBDEs) and other brominated flame retardants. Specific aims include: (1) To identify the sources of these potentially endocrine disrupting compounds (EDC) in the Hudson basin and changes in those sources overtime. To assess the contribution that municipal wastewater makes to EDC inputs to the Hudson Basin, specific chemical tracers for wastewater will be developed. (2) To determine the distribution and biogeochemical cycling of hydroxylated metabolites of PCBs (HO-PCBs) and PBDEs (HO-PBDEs) in sediments and food webs in the Hudson watershed. This research will determine whether EDCs persist and accumulate in sediments and whether HO-PCBs and HO-PBDE congeners enter aquatic food webs from exposure to sediments and/or consumption of aquatic invertebrates. (3) To identify through in vitro assay directed fractionation the spatial variation, likely sources, and identity of important estrogen and androgen agonists in sediments from the Hudson Basin. This aim will rely upon discovery-based mass spectrometric identification of putative structures. Assessment of the ecological and human health risks related to EDCs is a challenge because of the complexity of EDC mixtures and the many possible mechanisms through which EDCs may interact with endocrine systems. Much of the geochemical work to date with EDCs has focused on analysis of wastewater effluents and ambient water testing, rather than on examining sediments that are likely to be larger reservoirs of bioaccumulative and persistent EDCs. There is especially a lack of study of the identification and distributions of EDCs at sites heavily contaminated with Superfund chemicals. This project will seek to fill those gaps in information. It will link closely to basic biological and epidemiological research in the Mount Sinai SBRP that are elucidating mechanisms of toxicity, exploring gene-environment interactions and studying genetically determined, inter-individual differences in susceptibility to EDCs.